Systems and methods for selecting a welding process

ABSTRACT

Systems and methods for selecting a welding process are disclosed. An example welding power supply is configured to: provide welding power for welding; receive a communication from a remote device over a weld cable, wherein the communication corresponds to a detected welding output polarity; and automatically set a new welding process based on a current welding process of the welding power supply and the received communication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/537,147, filed Nov. 10, 2014, entitled “SYSTEMS AND METHODS FORSELECTING A WELDING PROCESS,” and claims priority from and the benefitof U.S. Provisional Patent Application Ser. No. 61/905,570, entitled“SYSTEMS AND METHODS FOR SELECTING A WELDING PROCESS,” filed Nov. 18,2013. The entireties of U.S. patent application Ser. No. 14/537,147 andU.S. Provisional Patent Application Ser. No. 61/905,570 are incorporatedherein by reference.

BACKGROUND

This disclosure relates generally to welding systems, and, moreparticularly, to systems and methods for selecting a welding process.

Welding is a process that has become increasingly prevalent in variousindustries and applications. Such processes may be automated in certaincontexts, although a large number of applications continue to exist formanual welding applications. In both cases, such welding applicationsrely on a variety of types of equipment to ensure that the supply ofwelding consumables (e.g., wire, shielding gas, etc.) is provided to theweld in an appropriate amount at the desired time. For example, metalinert gas (MIG) welding typically relies on a wire feeder to enable awelding wire to reach a welding torch. The wire is continuously fedduring welding to provide filler metal. A power source ensures that archeating is available to melt the filler metal and the underlying basemetal.

In certain applications, a welding operator may switch between a wireprocess mode (e.g., flux-cored arc welding (FCAW) with or without gas,MIG welding, etc.) and a non-wire process mode (e.g., stick welding,tungsten inert gas (TIG) welding, etc.). To switch between the wire andnon-wire process modes, the welding operator may connect and/ordisconnect a wire feeder from being coupled to the welding power supply.When switching between wire and non-wire process modes, it may bedifficult for the welding operator to properly select the correctprocess mode. For example, the welding operator may not be physicallylocated near the welding power supply and/or the welding operator maynot know whether welding cables are connected to the welding powersupply for direct current electrode negative (DCEN) or for directcurrent electrode positive (DCEP).

BRIEF DESCRIPTION

In one embodiment, a method includes detecting whether a wire feeder isin communication with a welding power supply. The method also includesdetecting a current welding process of the welding power supply if thewire feeder is in communication with the welding power supply. Themethod includes determining, at the wire feeder, a welding outputpolarity. The method also includes setting a new welding process basedon the current welding process and the welding output polarity without auser selecting the new welding process.

In another embodiment, an article of manufacture includes one or moretangible, non-transitory machine-readable media having encoded thereonprocessor-executable instructions. The instructions include instructionsto detect whether a wire feeder is in communication with a welding powersupply. The instructions also include instructions to detect a currentwelding process of the welding power supply if the wire feeder is incommunication with the welding power supply. The instructions includeinstructions to determine a welding output polarity. The instructionsalso include instructions to set a new welding process based on thecurrent welding process and the welding output polarity.

In another embodiment, a welding system includes a welding power supplyconfigured to provide welding power for a welding application. Thewelding system also includes a wire feeder configured to determine awelding output polarity. At least one of the welding power supply andthe wire feeder are configured to detect whether the wire feeder is incommunication with the welding power supply, to detect a current weldingprocess of the welding power supply if the wire feeder is incommunication with the welding power supply, and to set a new weldingprocess based on the current welding process and the welding outputpolarity without a user selecting the new welding process.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a block diagram of an embodiment of a welding system employinga wire feeder having polarity detection circuitry, in accordance withaspects of the present disclosure;

FIG. 2 is a flow chart of an embodiment of a method for selecting a newwelding process, in accordance with aspects of the present disclosure;

FIG. 3 is a diagram of an embodiment of a user interface of a weldingpower supply with stick welding mode selected, in accordance withaspects of the present disclosure;

FIG. 4 is a diagram of an embodiment of a user interface of a weldingpower supply with flux-cored arc welding (FCAW) no gas mode selected, inaccordance with aspects of the present disclosure; and

FIG. 5 is a diagram of an embodiment of a user interface of a weldingpower supply with FCAW with gas mode selected, in accordance withaspects of the present disclosure.

DETAILED DESCRIPTION

Turning now to the drawings, FIG. 1 is a block diagram of an embodimentof a welding system 10 employing a wire feeder having polarity detectioncircuitry. In the illustrated embodiment, the welding system 10 is aflux-cored arc welding (FCAW) welding system, although the presenttechniques may be used on other welding systems, such as other gas metalarc welding (GMAW) systems, and so forth. The welding system 10 powers,controls, and supplies consumables to a welding application. The weldingsystem 10 includes a welding power supply 12 and a voltage sensing wirefeeder 14.

The welding power supply 12 receives primary power 16 (e.g., from the ACpower grid, an engine/generator set, a battery, or other energygenerating or storage devices, or a combination thereof), conditions theprimary power, and provides an output power to one or more weldingdevices in accordance with demands of the system 10. The primary power16 may be supplied from an offsite location (i.e., the primary power mayoriginate from the power grid). Accordingly, the welding power supply 12includes power conversion circuitry 18 that may include circuit elementssuch as transformers, rectifiers, switches, and so forth, capable ofconverting the AC input power to AC or DC output power as dictated bythe demands of the system 10 (e.g., particular welding processes andregimes).

In some embodiments, the power conversion circuitry 18 may be configuredto convert the primary power 16 to both weld and auxiliary poweroutputs. However, in other embodiments, the power conversion circuitry18 may be adapted to convert primary power only to a weld power output,and a separate auxiliary converter may be provided to convert primarypower to auxiliary power. Still further, in some embodiments, thewelding power supply 12 may be adapted to receive a converted auxiliarypower output directly from a wall outlet. Indeed, any suitable powerconversion system or mechanism may be employed by the welding powersupply 12 to generate and supply both weld and auxiliary power.

The welding power supply 12 includes control circuitry 20 to control theoperation of the welding power supply 12. The welding power supply 12also includes a user interface 22. The control circuitry 20 may receiveinput from the user interface 22 through which a user may choose aprocess and input desired parameters (e.g., voltages, currents,particular pulsed or non-pulsed welding regimes, and so forth). The userinterface 22 may receive inputs using any input device, such as via akeypad, keyboard, buttons, touch screen, voice activation system,wireless device, etc. Furthermore, the control circuitry 20 may controlparameters input by the user as well as any other parameters.Specifically, the user interface 22 may include a display 24 forpresenting, showing, or indicating, information to an operator. Thecontrol circuitry 20 may also include interface circuitry forcommunicating data to other devices in the system 10, such as thevoltage sensing wire feeder 14. The welding power supply 12 includes atransceiver 26 for wirelessly communicating 28 with other weldingdevices. In the illustrated embodiments, the welding power supply 12 maycommunicate with other welding devices using a wired connection, such asby using a network interface controller (NIC) 30 to communicate data viaa network 32 (e.g., the Internet).

A gas supply 34 provides shielding gases, such as argon, helium, carbondioxide, and so forth, depending upon the welding application. Theshielding gas flows to a valve 36, which controls the flow of gas, andif desired, may be selected to allow for modulating or regulating theamount of gas supplied to a welding application. The valve 36 may beopened, closed, or otherwise operated by the control circuitry 20 toenable, inhibit, or control gas flow through the valve 36. For example,when the valve 36 is closed, shielding gas may be inhibited from flowingthrough the valve 36. Conversely, when the valve 36 is opened, shieldinggas may be enabled to flow through the valve 36. In certain embodiments,the welding system 10 may control the valve 36 such that data iscommunicated from the welding power supply 12 to the voltage sensingwire feeder 14 using data encoded within gas flow fluctuations (e.g.,via gas pulses within the flow of gas). Shielding gas exits the valve 36and flows through a cable or hose 38 (which in some implementations maybe packaged with the welding power output) to the voltage sensing wirefeeder 14 which provides the shielding gas to the welding application.As may be appreciated, certain embodiments of the welding system 10 maynot include the gas supply 34, the valve 36, and/or the hose 38.

Welding power flows through a cable 40 to the voltage sensing wirefeeder 14. The voltage sensing wire feeder 14 uses the welding power topower the various components in the voltage sensing wire feeder 14, suchas to power control circuitry 42. The welding power supply 12 may alsocommunicate with the voltage sensing wire feeder 14 using the cable 40.For example, the welding power supply 12 and/or the voltage sensing wirefeeder 14 may use weld cable communication (WCC) in which data isprovided over the welding power such that welding power and data areprovided together using a single conductor. WCC may be implemented asdescribed in U.S. patent application Ser. No. 12/912,452 which is herebyincorporated by reference in its entirety. Furthermore, the WCC may beimplemented using any suitable power line communication method.Accordingly, the welding power supply 12 includes WCC circuitry 39, andthe wire feeder 14 includes WCC circuitry 41 to facilitate communicationusing WCC between the welding power supply 12 and the wire feeder 14.Thus, using a single cable 40, welding power may be provided from thewelding power supply 12 to the voltage sensing wire feeder 14, and thewelding power supply 12 may communicate with the voltage sensing wirefeeder 14.

The control circuitry 42 controls the operations of the voltage sensingwire feeder 14. The control circuitry 42 includes at least onecontroller or processor 43 that controls the operations of the voltagesensing wire feeder 14, and may be configured to receive and processmultiple inputs regarding the performance and demands of the system 10.Furthermore, the processor 43 may include one or more microprocessors,such as one or more “general-purpose” microprocessors, one or morespecial-purpose microprocessors and/or ASICS, or some combinationthereof. For example, the processor 43 may include one or more reducedinstruction set (RISC) processors.

The control circuitry 42 may include a storage device 44 and a memorydevice 45. The storage device 44 (e.g., nonvolatile storage) may includeROM, flash memory, a hard drive, or any other suitable optical,magnetic, or solid-state storage medium, or a combination thereof. Thestorage device 44 may store data (e.g., data corresponding to a weldingapplication, etc.), instructions (e.g., software or firmware to performwelding processes), and any other suitable data. As may be appreciated,data that corresponds to a welding application may include an attitude(e.g., orientation) of a welding torch, a distance between the contacttip and a workpiece, a voltage, a current, welding device settings, andso forth.

The memory device 45 may include a volatile memory, such as randomaccess memory (RAM), and/or a nonvolatile memory, such as read-onlymemory (ROM). The memory device 45 may store a variety of informationand may be used for various purposes. For example, the memory device 45may store processor-executable instructions (e.g., firmware or software)for the processor 43 to execute. In addition, a variety of controlregimes for various welding processes, along with associated settingsand parameters, may be stored in the storage device 44 and/or memorydevice 45, along with code configured to provide a specific output(e.g., initiate wire feed, enable gas flow, capture welding currentdata, detect short circuit parameters, determine amount of spatter,etc.) during operation.

The control circuitry 42 includes polarity detection circuitry 46configured to detect whether the voltage sensing wire feeder 14 isconnected to the welding power supply 12 for direct current electrodenegative (DCEN) welding or for direct current electrode positive (DCEP)welding. As may be appreciated, the polarity detection circuitry 46 mayuse one or more diodes, transistors, switches, voltage monitors, currentmonitors, or any other suitable electronic device for determining thewelding output polarity. As described herein, in certain embodiments,the voltage sensing wire feeder 14 may use the control circuitry 42 todetect whether the voltage sensing wire feeder 14 is in communicationwith the welding power supply 12, to detect a current welding process ofthe welding power supply 12 if the voltage sensing wire feeder 14 is incommunication with the welding power supply 12, to determine a weldingoutput polarity (e.g., DCEN, DCEP, etc.), and to set a new weldingprocess based on the current welding process and the welding outputpolarity without a user selecting the new welding process (e.g.,automatically, without user intervention). Furthermore, in otherembodiments, the voltage sensing wire feeder 14 may be configured todetermine the welding output polarity, and at least one of the weldingpower supply 12 and the voltage sensing wire feeder 14 may use thecontrol circuitry 20 or 42 to detect whether the voltage sensing wirefeeder 14 is in communication with the welding power supply 12, todetect a current welding process of the welding power supply 12 if thevoltage sensing wire feeder 14 is in communication with the weldingpower supply 12, and to set a new welding process based on the currentwelding process and the welding output polarity without a user selectingthe new welding process (e.g., automatically, without userintervention).

In certain embodiments, the voltage sensing wire feeder 14 also includesa transceiver 47 for wirelessly communicating 48 with the welding powersupply 12, or another device (e.g., either directly or through anetwork). In certain embodiments, the transceiver 47 may be a Bluetoothdevice configured to communicate wirelessly with other devices.Moreover, the transceiver 47 may be used to transmit and/or receive datalogs, error codes, error information, or any other suitable data. In theillustrated embodiment, the voltage sensing wire feeder 14 maycommunicate with other welding devices using a wired connection, such asby using a NIC 50 to communicate data via the network 32. Moreover, thevoltage sensing wire feeder 14 may communicate via the network 32 usinga wireless connection.

The voltage sensing wire feeder 14 includes a user interface 52. Thecontrol circuitry 42 may receive input from the user interface 52, suchas via methods and devices described in relation to the user interface22. Moreover, the user interface 52 may include one or more buttons,touch screens, switches, etc. for enabling an operator to select one ofthe weld procedure memories. Furthermore, the control circuitry 42 maydisplay information (e.g., on a display of the user interface 52) to anoperator, such as voltage, current, wire speed, wire type, and so forth.A contactor 54 (e.g., high amperage relay) is controlled by the controlcircuitry 42 and configured to enable or inhibit welding power to flowto a weld power cable 56 for the welding application. In certainembodiments, the contactor 54 may be an electromechanical device, whilein other embodiments the contactor 54 may be any other suitable device,such as a solid state device. The voltage sensing wire feeder 14includes a wire drive 58 that receives control signals from the controlcircuit 42 to drive rollers 60 that rotate to pull wire off a spool 62of wire. The wire is provided to the welding application through a cable64. Likewise, the voltage sensing wire feeder 14 may provide shieldinggas through a cable 66. As may be appreciated, the cables 56, 64, and 66may be bundled together with a coupling device 68.

A torch 70 delivers the wire, welding power, and shielding gas for awelding application. The torch 70 is used to establish a welding arcbetween the torch 70 and a workpiece 74. A work cable 76, which may beterminated with a clamp 78 (or another power connecting device), couplesthe welding power supply 12 to the workpiece 74 to complete a weldingpower circuit. As illustrated, a voltage sense cable 80 is coupled fromthe voltage sensing wire feeder 14 to the workpiece 74 using a senseclamp 82 (or another power connecting mechanism). Accordingly, thevoltage sensing wire feeder 14 is connected to the welding power supply12 so that it may operate even when a welding arc is not formed by thetorch 70. Specifically, the voltage sensing wire feeder 14 receiveswelding power from the welding power supply 12 through cable 40. Thewelding power is connected to the various components in the voltagesensing wire feeder 14 (e.g., control circuitry 42, wire drive 58, userinterface 52). A return path for the voltage sensing wire feeder 14power is formed using the voltage sense cable 80 with the sense clamp 82connected to the workpiece 74. Further, the work cable 76 with the workclamp 78 provide the final portion of the return path to the weldingpower supply 12. Thus, the return path includes the cable 80, theworkpiece 74, and the cable 76. As may be appreciated, welding power mayflow in either direction through the conductive path formed by cables40, 56, and 76.

FIG. 2 is a flow chart of an embodiment of a method 90 for selecting anew welding process. The welding power supply 12 and/or the voltagesensing wire feeder 14 detects whether the voltage sensing wire feeder14 is in communication with the welding power supply 12 (block 92). Asmay be appreciated, the voltage sensing wire feeder 14 may use the WCCcircuitry 41, the control circuitry 42, the NIC 50, the transceiver 47,and/or any other suitable device to detect whether the voltage sensingwire feeder 14 is in communication with the welding power supply 12.Furthermore, the welding power supply may use the WCC circuitry 39, thecontrol circuitry 20, the NIC 30, the transceiver 26, and/or any othersuitable device to detect whether the welding power supply 12 is incommunication with the voltage sensing wire feeder 14. If communicationbetween the voltage sensing wire feeder 14 and the welding power supply12 is not established (block 94), the method returns to block 92.However, if communication between the voltage sensing wire feeder 14 andthe welding power supply 12 is established, the voltage sensing wirefeeder 14 determines a welding output polarity (block 96). For example,the voltage sensing wire feeder 14 uses the polarity detection circuitry46 to determine whether the welding output polarity is DCEP or DCEN. Asmay be appreciated, the welding power supply 12 and/or the voltagesensing wire feeder 14 may use the welding output polarity to set thenew welding process based on a current welding process and without auser selecting the new welding process (e.g., automatically, withoutuser intervention).

Accordingly, the welding power supply 12 and/or the voltage sensing wirefeeder 14 detects the current welding process of the welding powersupply 12 (block 98). For example, the welding power supply 12 and/orthe voltage sensing wire feeder 14 may detect whether the welding powersupply 12 is set to stick welding, tungsten inert gas (TIG) welding,FCAW no gas, and/or FCAW with gas, and so forth. Moreover, the weldingpower supply 12 and/or the voltage sensing wire feeder 14 may determineif the current welding process is a wire process mode (e.g., FCAW nogas, FCAW with gas, etc.) (block 100). If the current welding process isa wire process mode, the welding power supply 12 and/or the voltagesensing wire feeder 14 may instruct the welding power supply 12 to notchange the current welding process (e.g., set the new welding processequal to the current welding process) (block 102). Furthermore, thewelding power supply 12 and/or the voltage sensing wire feeder 14 maydetermine whether the welding output polarity is correct for the currentwelding process (block 104). In certain embodiments, the welding outputpolarity may be correct for the current welding process if the weldingoutput polarity is DCEN and the current welding process is FCAW withoutshielding gas. Moreover, in certain embodiments, the welding outputpolarity may be correct for the current welding process if the weldingoutput polarity is DCEP and the current welding process is FCAW withshielding gas.

If the welding output polarity is not correct, the welding power supply12 and/or the voltage sensing wire feeder 14 may provide feedback to thewelding operator indicating that the welding output polarity is notcorrect for the current welding process (block 106). For example, theuser interface 22 of the welding power supply 12 and/or the userinterface 52 of the voltage sensing wire feeder 14 may displayinformation indicating that the welding output polarity is not correctfor the current welding process. In certain embodiments, the weldingoutput polarity may be incorrect for the current welding process if thewelding output polarity is DCEP and the current welding process is FCAWwithout shielding gas. Moreover, in certain embodiments, the weldingoutput polarity may be incorrect for the current welding process if thewelding output polarity is DCEN and the current welding process is FCAWwith shielding gas.

If the current welding process is not a wire process mode, the weldingpower supply 12 and/or the voltage sensing wire feeder 14 may determinewhether the welding output polarity is DCEN (block 108). If the weldingoutput polarity is DCEN, the welding power supply 12 and/or the voltagesensing wire feeder 14 may instruct the welding power supply 12 tochange the current welding process to FCAW without shielding gas (e.g.,set the new welding process to FCAW without shielding gas) (block 110).However, if the welding output polarity is DCEP (e.g., not DCEN), thewelding power supply 12 and/or the voltage sensing wire feeder 14 mayinstruct the welding power supply 12 to change the current weldingprocess to FCAW with shielding gas (e.g., set the new welding process toFCAW with shielding gas) (block 112).

FIG. 3 is a diagram of an embodiment of the user interface 22 of thewelding power supply 12 with stick welding mode selected. Specifically,in the illustrated embodiment, the user interface 22 includes thefollowing process selections: FCAW no gas welding 116, lift-arc TIGwelding 118, scratch start TIG welding 120, stick welding 122, andMIG/FCAW with gas welding 124. A user input device 126 may be used by awelding operator to select a desired welding process. Moreover,indicators 128, 130, 132, 134, and 136 are used to show which process isselected. In the illustrated embodiment, stick welding 122 is selectedas shown by the indicator 134. As discussed above, the welding operatormay switch from stick welding 122 to a wire process mode by adding thevoltage sensing wire feeder 14 into the welding system 10 includinghaving the voltage sensing wire feeder 14 connected to the welding powersupply 12. A wire process is automatically selected by the weldingsystem 10 based on the welding output polarity without the weldingoperator making a new process selection (e.g., without userintervention). For example, if the welding output polarity is DCEN, FCAWno gas welding 116 is selected automatically (e.g., without userintervention) by the welding system 10 as illustrated by the indicator128 in FIG. 4. As another example, if the welding output polarity isDCEP, MIG/FCAW with gas welding 124 is selected automatically (e.g.,without user intervention) by the welding system 10 as illustrated bythe indicator 136 in FIG. 5. Thus, a wire process may be selected by thewelding system 10 when switching from a non-wire process mode to awire-process mode after reconfiguring the welding system 10. Whenswitching back to a non-wire process mode from a wire process mode, thewelding system 10 may automatically (e.g., without the welding operatormaking a selection, without user intervention) return the welding powersupply 12 to the previously used non-wire process mode.

As may be appreciated, by using the method 90 described herein, acorrect process mode may be selected with little to no process selectionmade on the welding power supply 12 by the welding operator. Forexample, a welding operator physically located away from a welding powersupply may have a correct process mode selected without the weldingoperator making the selection (e.g., the selection is made by thewelding system 10 after changing the welding configuration from anon-wire process mode to a wire-process mode).

While only certain features have been illustrated and described herein,many modifications and changes will occur to those skilled in the art.It is, therefore, to be understood that the appended claims are intendedto cover all such modifications and changes.

1. A welding power supply configured to: provide welding power forwelding; receive a communication from a remote device over a weld cable,wherein the communication corresponds to a detected welding outputpolarity; and automatically set a new welding process based on a currentwelding process of the welding power supply and the receivedcommunication.
 2. The welding power supply as defined in claim 1,wherein the welding power supply is configured to communicate with theremote device over the weld cable.
 3. The welding power supply asdefined in claim 1, wherein the welding power supply is configured tocommunicate with the remote device via a same conductor used to providethe welding power.
 4. The welding power supply as defined in claim 3,wherein the welding power supply is configured to: receive a secondcommunication from the remote device; and change one or more weldingprocess parameters based on the second communication.
 5. The weldingpower supply as defined in claim 1, wherein the communication isindicative of the welding output polarity.
 6. The welding power supplyas defined in claim 1, wherein the communication specifies the newwelding process.
 7. The welding power supply as defined in claim 1,wherein the welding power supply is capable of providing the weldingpower for a wire-process mode with weld gas, a wire-processor modewithout weld gas, a shielded metal arc welding mode, and a gas tungstenarc welding mode.
 8. A welding power supply, comprising: powerconversion circuitry configured to provide welding power for welding;communication circuitry configured to receive a communication from aremote device, the communication indicating a welding output polarity;and control circuitry configured to, based on a determination that thewelding power supply is in communication with the remote device andbased on the welding output polarity, set a new welding process withouta user selecting the new welding process.
 9. The welding power supply asdefined in claim 8, wherein the communication circuitry is configured tocommunicate with the welding power supply via a same conductor used toprovide the welding power.
 10. The welding power supply as defined inclaim 8, wherein the control circuitry is configured to set the newwelding process based on a current welding process.
 11. The weldingpower supply as defined in claim 8, wherein the communication circuitryis configured to receive a second communication from the remote device,and the control circuitry is configured to change one or more weldingprocess parameters based on the second communication.
 12. The weldingpower supply as defined in claim 8, wherein the communication isindicative of the welding output polarity.
 13. The welding power supplyas defined in claim 8, wherein the communication specifies the newwelding process.
 14. The welding power supply as defined in claim 8,wherein the power conversion circuitry is capable of providing thewelding power for a wire-process mode with weld gas, a wire-processormode without weld gas, a shielded metal arc welding mode, and a gastungsten arc welding mode.
 15. A method, comprising: detecting whether aremote device is in communication with a welding power supply;determining a current welding process of the welding power supply; basedon receiving a communication from the remote device, the communicationbased on a welding output polarity, setting a new welding process basedon the communication without a user selecting the new welding process.16. The method as defined in claim 15, wherein the detecting whether theremote device is in communication with the welding power supply is via asame conductor used to provide welding power.
 17. The method as definedin claim 16, further comprising: receiving a second communication fromthe remote device via the conductor; and change one or more weldingprocess parameters based on the second communication.
 18. The method asdefined in claim 15, wherein the communication is indicative of thewelding output polarity.
 19. The method as defined in claim 15, whereinthe communication specifies the new welding process.
 20. The method asdefined in claim 15, further comprising providing welding power for oneof wire-process mode with weld gas, a wire-processor mode without weldgas, a shielded metal arc welding mode, or a gas tungsten arc weldingmode.